By Michael Gray
On August 10, 2015, Dr. Doug Johnson, an Extension Entomologist with the University of Kentucky reported that the sugarcane aphid, Melanaphis sacchari (Zehntner), was collected in two western Kentucky counties (Fulton County and Graves County) on grain and sweet sorghum. The identity of the aphids was confirmed by Dr. Lee Townsend, Extension Entomologist, University of Kentucky. To date, this aphid has largely affected sorghum producers in several southeastern states as well as Kansas, Missouri, and Texas. Recently, I received calls from growers and representatives of the private sector that some grain sorghum fields in southern Illinois were infested with this pest. Counties specifically referenced included Massac, Pope, and Williamson. Infestations have been observed in fields as far north as those located near Marion, Illinois. These observations are not surprising in light of the recently confirmed infestations in nearby locations in Kentucky. Late-planted sorghum is most at risk to severe yield losses; however, the excessive amount of honeydew created by large densities of sugarcane aphids may create significant harvest difficulties even in earlier planted fields. Several affected fields in southern Illinois have been described as “glazed” over with this sticky material. Plants covered with honeydew can significantly interfere with an efficient harvest. Dr. Doug Johnson provided some good background and management information on sugarcane aphids in a June 2 Kentucky Pest News article.
Currently, the Illinois Department of Agriculture is in the process of requesting a Section 18 Emergency Exemption for the insecticide Transform WG (active ingredient – sulfoxaflor) manufactured by Dow AgroSciences. Efficacy data generated by other states indicate that this product has performed well against sugarcane aphids. However, at this point, a Section 18 Emergency Exemption request has not yet been approved for Illinois by the United States EPA.
Another product that has received some consideration for use against sugarcane aphids is Sivanto (flupyradifurone) 200 SL (Bayer). In Dr. Johnson’s August 10 article, he indicated that this insecticide could be targeted at sugarcane aphids with the manufacturer’s 2ee recommendation. The applicator is required to have a label in hand during the application.
I encourage growers to scout their grain sorghum fields for sugarcane aphids and review the articles that I have referenced that were prepared by Dr. Doug Johnson. Also, I will alert producers as to the status of the Section 18 request.